Configuration Setup Help

I have been working for like 3 days trying to figure out how to get the Line-in to come through the Mic area,
I am running a Internet radio station, I have a 8 channel sound board with sound effects my Boom-mic hooks into that and then a connection from the DJ board goes to the Line-in port in the back of the PC. I have figured out how to get the broadcast to go and I can broadcast the music from the machine just fine , but when I go to talk on the mic all I get is a rasty sound coming out and you cannot understand nothing being said.

My problem is trying to find which connection needs to be hooked and what needs to be turned down,,
Basically I was looking for a help guide and really haven't found nothing that helps in this due to the program naming all sound devices the same thing so its a little confusing.
I found the settings to turn the Line-in up and activate it in a terminal window so thats all set,,,, just tring to figure out what goes were after wards is blowing me away.

Running : Asus Motherboard Dual Core 3.2
6 gig of 1333 mhz ram
10 Terabyte Hdd
100/1000 dlink Network card
Add-ons : 8 channel Soundboard Dual EQ's
inputs are sound comes out from the PC via Speaker/RCA cord
outputs are goes back in from the sound board to Line-in via Speaker/RCA cord
OS" Pinguy latest version
updates and all drivers loaded

Any help on this would be appreciated!!! Thanks